[Study of hypertrophic cardiomyopathies with Doppler echocardiography]

The aim of this review is to demonstrate the usefulness of Doppler echocardiography in the study of hypertrophic cardiomyopathy. Two-dimensional imaging enables confirmation of hypertrophy and identification of its type (usually asymmetrical), site and extent. Intraventricular obstruction can be confirmed by echocardiography (mesosystolic aortic closure, systolic anterior mitral movement with prolonged septal contact) and Doppler (intraventricular obstruction flow). This obstruction may be obvious (present under baseline conditions), latent (appearing during provocative tests) or absent. The maximum velocity of obstruction flow can be used to calculate intraventricular gradient by application of Bernouilli's equation. This intraventricular obstruction flow must be distinguished from apical obliteration flow (with which it may be associated) and from left mid-ventricular stenosis flow (which may cause diastolic obstruction associated with the systolic obstruction). Mitral insufficiency is usually a consequence of intraventricular obstruction (loss of systolic coaptation of the mitral leaflets secondary to systolic anterior mitral movement). Ejection parameters are increased because of a fall in left ventricular afterload (hyperdynamic state). Left ventricular diastolic function is most often abnormal (relaxation anomaly). Doppler echocardiography can also be used to seek associated abnormalities, in the evaluation of family members and to monitor progress (treated or not treated). Doppler echocardiography thus enables complete anatomical and functional study of hypertrophic cardiomyopathy. Invasive hemodynamic investigations are justified only if a diagnostic problem persists, if surgical treatment is considered or if coronary arteriography is thought necessary.